1. Field of the Invention
This invention is directed to ammunition cartridges including shotshell wads wherein the cartridges are of the type used with shot guns and, more specifically, to such cartridges which have a shotshell wad which defines a rear charge receiving chamber and at least two forward shot or other projectile receiving chambers.
2. History of the Related Art
Early ammunition of the type used with shot guns included shell casings in which a plurality of lead shot pellets were housed. Upon firing, the lead shot pellets would exit the barrel of the gun. As lead is a soft metal, the lead shot would not score or damage the interior of the barrel of the gun. However, as the art has progressed, steel pellets are now commonly employed in lieu of lead shot. As steel is a harder material than lead, the steel can score and damage the interior of the bore of the barrel of a gun. In view of this, shotshell wads were developed made of paper and plastic for purposes of housing and carrying the shot forwardly along the interior of the barrel so as to prevent the shot from coming into direct contact with the surface of the bore and, thus, preventing damage to the barrel. When fired, the shotshell wad is designed to carry the load of shot pellets forwardly of the barrel and out of the muzzle area toward a target. Over the years, there have been many improvements made with respect to the design and construction of the shotshell wads in order to affect more control over the type of dispersion of the contained shot pellets and to prevent tumbling of the shotshell wads after exiting the muzzle of a gun after being fired.
In addition to the improvements being made to the shotshell wad casings, there has also been development in the manner in which the shot charges disburse when a cartridge is fired. The degree of spread of the shot pattern can be effected by the manner in which not only the shot is packed, but upon how the surrounding shotshell wad is formed. Generally, when shot pellets are unbound within a conventional shotshell wad, there is a fairly broad pattern obtained upon a cartridge being fired toward a target. Such spreading of the shot pellets reduces the effective point impact of the total shot charge with a target. Therefore, in some shotshell wads, efforts have been made to bind or pack the shot pellets to obtain a more closely packed pattern of shot pellets at the point of impact with a target.
By way of example, in U.S. Pat. No. 3,656,433 to Thraikill et al., flechettes or other small missiles or shot are placed within a viscoelastic matrix, such that when fired, the flechettes, or shot, form a unitary projectile which emerges from a gun barrel until it passes a region at the front end of muzzle of the barrel, afterwhich the flechettes separates, thereby reducing the scattering of the flechettes or other shot. To further control the pattern of missile or shot trajectory until impact with a target, in U.S. Pat. No. 4,913,054 to Peterson, cartridges are disclosed wherein the missiles or shot elements are bound in a friable capsule including a material which becomes rapidly pliable or melts when impacted with a target. Such material may be a polyvinylchloride (PVC) type material. With such a cartridge, the projectile, upon firing, remains substantially intact within the shotshell wad until impact with a target at which time the interior shot or missiles are released, as the surrounding binding material melts or breaks free by the force and the heat developed at impact with the target. Therefore, substantially all the shot or missiles are concentrated at the point of impact.
In view of the foregoing, there remains a need to form cartridges which contain shot pellets or other projectiles wherein the benefits of retaining a compact pattern of pellets until point of impact with the target is achieved but wherein a dispersion of pellets is also obtained so as to diversify the spread of pellets at the point of impact with a target.
Some other examples of prior art patents are disclosed in the U.S. Pat. No. 34,806 to Budd, U.S. Pat. No. 3,092,026 to Williams et al., U.S. Pat. No. 3,132,588 to Schafer, U.S. Pat. No. 3,422,761 to Whitmore, U.S. Pat. No. 3,599,568 Shellmett, and U.S. Pat. No. 4,996,923 to Theising.
This invention is directed to ammunition cartridges which include a shotshell wad for retaining shot pellets or other projectiles and wherein the shotshell wad includes a rearwardly oriented charge receiving chamber and at least two forwardly oriented shot or other projectile receiving chambers. At least one of the at least two projectile receiving chambers includes projectiles, such as shot pellets, which are unbound with respect to one another, and a forward, of the at least two projectile receiving chambers, is formed as a hardened disk including a plurality of shot pellets or projectiles embedded within a hardened binder material. When the cartridges are fired, the foremost hardened disk will retain the unbound shot pellets generally concentrated within the shotshell wad until impact is made with a target afterwhich, the unbound missiles are permitted to diversify or spread relative to the target.
In a preferred embodiment of the present invention, the hardened disk is formed of a single layer of shot pellets which are embedded within a plastic or adhesive melt. The disk is positioned between dividers within the forward end of a shotshell wad so as to be spaced forwardly of a chamber in which unbound shot pellets are housed, with the unbound shot pellets being separated from the rear charge receiving chamber by an internal partition which is preferably integrally formed with the shotshell wad.
In some embodiments of the invention, the rear portion of the shotshell wad which extends along the charge receiving chamber may include a plurality of wall scores or lines of weakness which extend generally parallel to a longitudinal axis of the shotshell wad. The exterior wall of the shotshell wad along the charge receiving chamber will separate into a plurality of segments which flare radially outwardly upon firing of the shotshell wad from the barrel of a gun, thus facilitating the stability of the flight of the shotshell wad so as to reduce the effect of possible tumbling of the shotshell wad as it moves toward a target.
In other embodiments of the present invention, spaced segments of the rear projectile receiving portion of the shotshell wad may be scored or severed so as to expand outwardly or open in an area adjacent to an internal partition dividing the projectile receiving chambers from the charge receiving chamber so as to thereby reduce pressure within the projectile receiving chamber in which the unbound shot charge is housed. This action will reduce the effect of force packing the shot pellets within the shotshell wad upon firing of a cartridge.
It is a primary object of the present invention to provide an ammunition cartridge for use with guns, such as shot guns, wherein at least two separate projectile receiving chambers are provided within a shotshell wad of the cartridge with a forward of the chambers being formed so as to provide a solid and bound shot pellet structure for providing concentrated impact force with a target and which solid structure retains an unbound charge of shot pellets more concentrated until point of impact with the target afterwhich, the unbound shot pellets disburse in random pattern relative to the target.
It is yet another object of the present invention to provide ammunition cartridges which provide a two-fold impact effect by providing substantial concentrated point impact of a discharged round with a target while also allowing a disbursal of unpacked shot pellets or other projectiles when the round impacts a target.
It is a further object of the present invention to provide ammunition cartridges of the type used for shot guns wherein separate shot dispersions are achieved at the point of impact of a round with a target and wherein the control of the movement of a shotshell wad containing the shot elements is effected by forming the shotshell wad casing so as to control the flight of the shotshell wad and also control internal pressure within the shotshell wad to further enhance dispersion of unbound shot at the point of impact with a target.